Memories have a way of informing our identities, reinforcing our conceptions of who we are, and helping shape us into the people we will become tomorrow. In almost all cases, our memories — even the unpleasant ones — play a formative role in our lives; but they can also be so painful or traumatic that they become become debilitating.

In the latest issue of Wired, Jonah Lehrer provides us with a detailed look at a future where editing our memories could become a reality. We're not talking Eternal Sunshine of the Spotless Mind style brain-wipes; the memory-editing of the future will offer incredible precision, allowing us to address the neurological underpinnings responsible for everything from post-traumatic stress disorder, to drug addiction, to regret over a one-night stand.

Lehrer's feature explores in illuminating detail the status of research into "forgetting pills;" the incredible potential of such treatments; and the social, behavioral, and ethical hangups of rewriting one's personal history. We've included an excerpt here, but you'll definitely want to read the rest over on Wired.

[Our present] understanding of how memories are created emerged in the 1970s. But what happens after a memory is formed, when we attempt to access it, was much less well understood. In the late 1990s, Karim Nader, a young neuroscientist studying emotional response at New York University, realized that no one knew. "My big advantage was that I wasn't trained in memory," Nader says. "I was very naive about the subject. Even though the field wasn't that interested in the mechanisms of recall, it struck me as a mystery worth pursuing."

He began with the simplest question he could think of. While it was clear that new proteins were needed for the making of memories-proteins are cellular bricks and mortar, the basis of any new biological construction-were additional proteins made when those memories were recalled? Nader hypothesized that they were, and he realized that he could test his notion by temporarily blocking protein synthesis in a brain and looking to see if that altered recall. "This is the kind of question you ask when you don't know how else to approach the subject," Nader says. "But I had to do something, so why not this?"

His boss, the famed neuroscientist Joseph LeDoux, couldn't have been more discouraging. "I told Karim he was wasting his time," LeDoux says. "I didn't think the experiment would work." To LeDoux, the reason was obvious: Even if Nader blocked protein synthesis during recall, the original circuitry would still be intact, so the memory should be too. If Nader could induce amnesia, it would be temporary. Once the block was removed, the recall would return as strong as ever. And so LeDoux and Nader made a bet: If Nader failed to permanently erase a set of fear memories in four lab animals, he had to buy LeDoux a bottle of tequila. If it worked, drinks were on LeDoux. "I honestly assumed I'd be spending a bunch of money on alcohol," Nader says. "Everyone else knew a lot more about the neuroscience of memory. And they all told me it would never work."

He taught several dozen rats to associate a loud noise with a mild but painful electric shock. It terrified them-whenever the sound played, the rats froze in fear, anticipating the shock. After reinforcing this memory for several weeks, Nader hit the rats with the noise once again, but this time he then injected their brains with a chemical that inhibited protein synthesis. Then he played the sound again. "I couldn't believe what happened," Nader says. "The fear memory was gone. The rats had forgotten everything." The absence of fear persisted even after the injection wore off.